JPH0262449A - V-belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To make it possible to center a movable wall on the side of a movable disk becoming the reference in the time of axial movement by fitting and fixing the movable wall forming the second cylinder chamber of a tandem type hydraulic cylinder to the first cylindrical cylinder wall protruding from the movable disk through the step section. CONSTITUTION:When working pressure is supplied from the passages 42 and 42a of a continuously variable transmission 10 to the first cylinder chamber 36, a movable disk 22 is directly pressed toward the fixed disk 18. At the same time, when working pressure is supplied from a passage 30b to the second cylinder chamber 38, a movable wall 34 is moved to transmit the working pressure to the movable disk 22, and the working pressure moves the disk 22 with the help of the pressing force of the cylinder chamber 36, which makes the width of a pulley groove 24. This increases the circular radius of a V belt 26 allowing the speed change ratio to an output pulley to be set at large value. When hydraulic pressure is eliminated from the cylinder chambers 36 and 38, the disk 22 and movable wall 34 are separated from the disk 18 by the tension of the belt 26, and the circular radius of the belt 26 is reduced, and the speed change ratio to the output pulley is set at small value.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a V-belt type continuously variable transmission, and more particularly to a V-belt type continuously variable transmission in which a variable width pulley is driven via a tandem type hydraulic cylinder. Regarding continuously variable transmissions.

2. Description of the Related Art This type of V-belt continuously variable transmission includes, for example, one disclosed in Japanese Patent Laid-Open No. 57-129953, in which a tandem transmission is used to drive a primary pulley configured as a variable width pulley. type hydraulic cylinder (hydraulic servo) is used.

That is, the tandem-type hydraulic cylinder has a first cylindrical cylinder wall (cylindrical wall) formed on the outer periphery of a movable disk (movable flange) of the briny boob, and a first cylindrical cylinder wall that fits into the inner periphery of the first cylindrical cylinder wall. A first fixed wall (first piston) that is fitted together and has a cylindrical portion formed on its inner circumference, and a second cylindrical cylinder wall (peripheral wall) that covers the outer periphery of the first cylindrical cylinder wall. 2 fixed wall (cylinder), and a movable wall (second piston) whose inner periphery is slidably fitted into the cylindrical part and whose outer periphery is slidably fitted into the second cylindrical cylinder wall.
It is composed of.

- Hydraulic pressure is supplied to a first cylinder chamber formed between the movable disk and the first fixed wall and a second cylinder chamber formed between the second fixed wall and the movable wall. By doing so, the movable disk is directly pressed by the hydraulic pressure in the first cylinder chamber, and the hydraulic pressure in the second cylinder chamber acts on the movable disk through the movable wall, so that the movable disk is pressed in the same direction. The configuration is as follows.

Problems to be Solved by the Invention However, in such a conventional V-belt type continuously variable transmission, the movable wall is fitted between the cylindrical portion of the first fixed wall and the second cylindrical cylinder wall. Due to the supported configuration, the centering of the movable wall is carried out independently of the movable disk that serves as a reference during axial movement.

Therefore, the movable wall is fitted with relatively large tolerances to accommodate concentric formation errors between the movable disk and the cylindrical portion and the second cylindrical cylinder wall.

For this reason, the movable wall is likely to be strained between the cylindrical portion and the second cylindrical cylinder wall, and there is a problem in that efficiency may deteriorate or parts may be damaged due to malfunction of the movable wall. Ta.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a V-belt type continuously variable transmission configured such that centering of a movable wall can be performed using a movable disk that serves as a reference during axial movement.

Means for Solving the Problems In order to achieve the above object, the present invention includes a fixed disk provided integrally with a support shaft, and a fixed disk disposed opposite to the fixed disk, movable in the axial direction and rotatable integrally with the support shaft. A V-belt comprising a variable width pulley consisting of a movable disk that is fitted, a tandem hydraulic cylinder provided between the back surface of the movable disk and the support shaft, and which moves the movable disk in the axial direction by the hydraulic cylinder. In the continuously variable transmission, the tandem hydraulic cylinder is connected to a first support shaft that is concentric with the support shaft that protrudes from the outer periphery of the movable disk toward the rear.
a cylindrical cylinder wall; and a cylindrical part is fitted to the inner circumference of the first cylindrical cylinder wall so as to be relatively slidable therein, and a cylindrical part concentric with the support shaft is formed on the inner circumference; a first fixed wall fixed to the shaft and forming a first cylinder chamber between the two movable disks; a second cylindrical cylinder wall that overlaps is provided on the outer periphery and is fixed to the support shaft; - between the outer periphery of the cylindrical portion and the inner periphery of the second cylindrical cylinder wall; a movable wall that is slidably fitted to the second fixed wall and forms a second cylinder chamber between the movable wall and the movable wall, the movable wall having a stepped portion, and the stepped portion being connected to the first cylinder. It is constructed by fitting and fixing to the tip of the shaped cylinder wall.

In the V-belt type continuously variable transmission of the present invention, the movable disk is directly pressed by the hydraulic pressure supplied to the first cylinder chamber, and the hydraulic pressure is supplied to the second cylinder chamber. As a result, the movable wall slides between the cylindrical portion of the first fixed wall and the second cylindrical cylinder wall, and presses the movable disk in the same direction as the first cylinder chamber.

By the way, the fixed wall that slides between the cylindrical part and the second cylindrical cylinder wall is connected to the first cylindrical cylinder wall that protrudes from the movable disk via a stepped part formed in the fixed wall. Due to the fitted fit, the fixed wall can be centered on the movable disk via the first cylindrical cylinder wall.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIGS. 1 and 2 are sectional views of main parts of a V-belt type continuously variable transmission 10 showing one embodiment of the present invention, and the case where the present invention is applied to the input pulley 12 side will be explained as an example.

In FIG. 1, reference numeral 14 denotes an input shaft (not shown) serving as a support shaft to which engine power is manually applied, and the end of the input shaft 14 is rotatably supported on the housing 1 side via a bearing 16.

The input pulley 12 is configured as a variable width pulley, and includes a fixed disc 18 integrally protruding from the input shaft 14, and is arranged opposite to the fixed disc 18, and is connected to the input shaft 14 via a ball spline 20 so that the input pulley can be operated by the human operator. A movable disc 22 is fitted to the shaft 14 so as to be rotatable integrally with the shaft 14 and movable in the axial direction, and a single-shaped pulley groove 24 is formed between the fixed disc 18 and the movable disc 22. Ru.

A V-belt 26 for transmitting power to an output pulley (not shown) is wound around the boob groove 24.

By the way, a tandem type hydraulic cylinder 28 is provided on the back surface (left side in the figure) of the movable disk 22, and the movable disk 22 is moved in the axial direction by the tandem type hydraulic cylinder 28, thereby changing the width of the pulley groove 24. By changing this, the circumferential radius of the V-belt 26 is adjusted.

The tandem hydraulic cylinder 28 has a movable disk 22
A first cylindrical cylinder wall 22a protruding from the outer periphery toward the rear side, a first fixed wall 30, and a second fixed wall 32, which will be described later.
, and a movable wall 34.

The first cylindrical cylinder wall 22a projects integrally from the movable disk 22 and is formed as a cylindrical body concentric with the input shaft 14.

The first fixed wall 30 has an outer periphery fitted to the inner periphery of the first cylindrical cylinder wall 22a so as to be relatively slidable, and an inner periphery thereof has a housing boss portion 22b of the ball spline 20 of the movable disk 22. A cylindrical part 30a formed concentrically with the human power shaft 14 is provided to cover the manpower shaft 14. Then, the first fixed wall 3
The inner circumference of 0 is fitted to the input shaft 14 .

The second fixed wall 32 has an outer peripheral portion that covers the outside of the first cylindrical cylinder wall 22H.
A second cylindrical cylinder wall 32 a is formed which overlaps the fixed wall a in the axial direction, and the inner circumference of the second fixed wall 32 is fitted into the input shaft 14 .

and the first
The fixed wall 30 and the second fixed wall 32 are sandwiched between the stepped portion 14a formed on the manpower shaft 14 and the bearing 16, and are tightened together with a nut N. A second cylindrical cylinder wall 30 32 is fixed to the input shaft 14 .

On the other hand, the movable wall 34 has a jaw portion 34a formed on its outer periphery, and the outer periphery of the jaw portion 34a is formed on the second cylindrical cylinder wall 32a.
The inner periphery of the movable wall 34 is slidably fitted to the inner periphery of the cylindrical portion 30a of the first fixed wall 30.
Slidably fitted.

A step portion 34b provided below the jaw portion 34a
The outer periphery of the tip of the first cylindrical cylinder wall 22a is press-fitted into the inner periphery of the cylinder wall 22a.

A space defined by the movable disk 22 and the first fixed wall 30 is a first cylinder chamber 36, and a space defined by the second fixed wall 32 and the movable wall 34. The space defined by the first fixed wall 30 and the movable wall 34 is the air chamber 40.
It is said that

By the way, there is a hydraulic pressure supply passage 42 inside the human power shaft 14.
is formed, and the working hydraulic pressure introduced into the hydraulic pressure supply passage 42 is transmitted through a passage 42a formed in the radial direction of the input shaft 14.
The first fixed wall 30 communicates with the first cylinder chamber 36 through the passageway 30b, and further communicates with the second cylinder chamber 38 through a passage 30b formed in the inner circumference of the first fixed wall 30.

Further, the air chamber 40 is communicated with the atmosphere through a slit 22C formed at the tip of the first cylindrical cylinder wall 32a, so that the volume inside the air chamber 40 can be easily changed. .

With the above configuration, the V-belt type continuously variable transmission 10 of this embodiment
In this case, by supplying hydraulic pressure to the first cylinder chamber 36 through the passage 42 and the passage 42a, the movable disk 22 is directly pressed in the direction of the fixed disk 18, and further through the passage 30b. The movable wall 34 is moved by supplying hydraulic pressure to the second cylinder chamber 38, and the moving force of the movable wall 34 is transmitted to the movable disk 22 press-fitted therein, causing the first cylinder chamber 36 to be pushed. The movable disk 22 is moved in the same direction with the pressure, and the boe groove 2 is moved.
Narrow the width of 4.

Then, the circumferential radius of the V-belt 26 wound around the input converter pulley 12 becomes larger, and the gear ratio transmitted to the output pulley (not shown) is set larger.

On the other hand, the above 1. By removing hydraulic pressure from the second cylinder chamber 36.38, the movable disk 22 and the movable wall 3
4 is moved away from the fixed disk 18 by the tension of the V-belt 26, and the circumferential radius of the V-belt 26 is small (
Therefore, the gear ratio is set small for the output boom.

By the way, when the movable wall 34 is moved in the axial direction, it slides between the outer periphery of the cylindrical portion 30a of the first fixed wall 30 and the inner periphery of the second cylindrical cylinder wall 32a. Movable wall 3
4 is fitted with the first cylindrical cylinder wall 22a protruding from the movable disk 22 with a stepped portion 34b formed thereon, whereby the movable wall 34 can be centered on the movable disk 22 side, The radial accuracy of the movable wall 34 is significantly improved.

Therefore, when the movable wall 34 is moved, the cylindrical portion 3
0a and the first cylindrical cylinder wall 22a, and the tandem hydraulic cylinder 2
8 can be performed smoothly, and the moving position of the movable disk 22 can be adjusted as set.

In the tandem hydraulic cylinder 28 of this embodiment, a first cylindrical cylinder wall 22a forming the outer wall of the first cylinder chamber 36 and a second cylindrical cylinder wall 22a forming the outer wall of the second cylinder chamber 38 are used. Since the cylinder wall 32a is configured to overlap in the axial direction, the tandem hydraulic cylinder 28
can be shortened in the axial direction.

DETAILED DESCRIPTION OF THE INVENTION As described above, in the V-belt continuously variable transmission of the present invention, the movable wall that constitutes the second cylinder chamber of the tandem J12 hydraulic cylinder is moved through the stepped portion formed therein. Since it is fitted and fixed to the first cylindrical cylinder wall protruding from the movable disk, the movable wall can be centered on the movable disk side which serves as a reference during axial movement.

Therefore, the fitting precision in the radial direction of the movable wall can be significantly improved, and when the movable wall is moved, the inner and outer peripheries of the movable wall are fitted into the cylindrical portion of the first fixed wall and the second fixed wall. This prevents straining between the wall and the cylindrical cylinder wall, allowing smooth operation of the tandem hydraulic cylinder.

For this reason, the pulley groove width of the variable width pulley can be adjusted to a preset amount with high precision, and the speed ratio of the V-belt type continuously variable transmission can be set as desired, which is an excellent effect. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention, and 2N is an enlarged sectional view of section A in FIG. 1. 10...V-belt type continuously variable transmission, 12...Man caboori (variable width pulley), 14...Manpower shaft (support shaft), I
8... Fixed disk, 22... Movable disk, 22
a... first cylindrical cylinder wall, 24... boob groove,
2G... V belt, 28... Tandem type hydraulic cylinder, 30... First fixed wall, 30a... Cylindrical part, 32
...Second fixed wall, 32a...Second cylindrical cylinder wall, 34...Movable wall, 34b...Step part, 36...First cylinder chamber, 38...Second cylinder chamber . +θ ~' Belt type continuously variable transmission 2 Human power pulley (variable width pulley) 4 Human power shaft (support shaft) 18 Fixed disk 22 Movable disk 22a 1st no. Norinoda 30 First fixed wall 30a - cylindrical part 32 Second fixed wall 32a First nonoda chamber 34 Movable wall 34b Step part 36 First nonoda chamber 38 Brown second nori noda chamber 2a

Claims (1)

[Claims] (1) A variable width pulley consisting of a fixed disk provided integrally with the support shaft and a movable disk disposed opposite to the fixed disk and fitted to the support shaft so as to be movable in the axial direction and rotatably integral with the support shaft; A V-belt type continuously variable transmission in which a tandem hydraulic cylinder is provided between the back surface of the movable disk and the support shaft, and the movable disk is moved in the axial direction by the hydraulic cylinder, the tandem hydraulic cylinder comprising: A first shaft concentric with the support shaft protruding from the outer periphery of the movable disk toward the rear surface.
a cylindrical cylinder wall; and a cylindrical part is fitted to the inner circumference of the first cylindrical cylinder wall so as to be relatively slidable therein, and a cylindrical part concentric with the support shaft is formed on the inner circumference; a first fixed wall fixed to a shaft and forming a first cylinder chamber between the movable disk; and a first fixed wall that covers the outside of the first cylindrical cylinder wall and overlaps the first cylindrical cylinder wall in the axial direction. a second fixed wall fixed to the support shaft; and a second fixed wall that slides between the outer circumference of the cylindrical portion and the inner circumference of the second cylindrical cylinder wall. a movable wall that is able to be fitted to the second fixed wall to form a second cylinder chamber; a step is formed in the movable wall, and the step is connected to the first cylindrical cylinder wall; A V-belt type continuously variable transmission characterized by being fitted and fixed to the tip of the V-belt type continuously variable transmission.